1. Filed of the Invention
The present disclosure relates to an electrolytic copper foil for a lithium secondary battery and a lithium secondary battery comprising the same, and more particularly, to an electrolytic copper foil for a lithium secondary battery and a lithium secondary battery comprising the same, which does not acquire wrinkles at an uncoated portion after coating during a battery manufacturing process, by adjusting an elongation increment ratio with respect to a thermal treatment temperature within a predetermined range.
2. Description of Related Art
A lithium secondary battery has many advantages such as relatively high energy density, high operation voltage, excellent preservation and long life span in comparison to other secondary batteries, and thus the lithium secondary battery is widely used for various portable electronic devices such as personal computers, camcorders, cellular phones, CD players, PDA or the like.
Generally, a lithium secondary battery includes a positive electrode and a negative electrode disposed with an electrolyte being interposed between them. Here, the positive electrode is configured so that a positive electrode active material is attached to a positive electrode current collector, and the negative electrode is configured so that a negative electrode active material is attached to a negative electrode current collector.
In the lithium secondary battery, the negative electrode current collector is generally made of an electrolytic copper foil, and the electrolytic copper foil should have excellent properties so that the performance of the secondary battery is maintained even though severe conditions are repeatedly formed in the secondary battery as the secondary battery is charged and discharged.
As a property required for the electrolytic copper foil, for example, the electrolytic copper foil should not be torn even though severe conditions are repeated due to charging and discharging.
Meanwhile, such excellent properties of the electrolytic copper foil may be ensured by adjusting various factors, but it is very difficult to find which factor should be adjusted and how much the factor should be adjusted in order to obtain desired properties.